CNC Machined Part: Causes Of Dimensional Errors And Adjustment Methods

Sep. 10, 2021

CNC Machined Part

CNC lathes mainly process rotary parts. The main components of most parts are holes, outer circles, grooves, and threads. This article analyzes the causes of machining errors in parts, and studies how to solve them and avoid recurrence.


Causes of errors in part processing

Insufficient machine tool rigidity and tool rigidity

In the process of processing the workpiece, the surface quality of the parts is too poor due to the excessive processing volume and insufficient machine rigidity. The tool wears faster during the excessive cutting process. The surface quality of the workpiece is too poor, and even the tool is broken.

Machining tool wear

When machining parts on a CNC lathe, the tool will wear out. When machining the outer circle, the outer circle size will increase after the tool is worn, which will cause the size to be out of tolerance. In the process of machining the inner hole, the size of the inner hole will become smaller after the tool is worn, causing the size to be out of tolerance. When processing threaded parts, after the thread cutter is worn, the internal and external threads are out of tolerance, and the ring gauge and plug gauge are not qualified.

Technician error

After the tool and workpiece are installed, the technician enters the program and debugs. Tool setting and size measurement are required during the commissioning process. When setting tool length compensation, the accuracy of the processed parts will be out of tolerance due to operating errors.

Insufficient coolant supply

In the process of metal processing, due to the high cutting speed, a large amount of heat is generated. In the cutting process, if the cooling is not timely enough, a large amount of iron cutting will occur. They will wrap around the work piece and damage the tool, resulting in the final size being out of tolerance.


CNC Machined Part

Solutions to the size of parts processed by CNC lathes are out of tolerance

1.In the process of CNC lathe processing, after the size is out of tolerance due to the above problems, we must promptly debug and replace the tools to reduce losses.

2. When measuring the outer circle, if the length of the outer circle surface of the dimension is too long, we need to measure in sections. After finding that the outer circle has a taper, it needs to be debugged through the program.

3. After performing routine inspections and correct judgments, the operator can well control the size of common parts processed by CNC lathes in accordance with the above debugging methods. In the process of processing, the operator must submit for inspection and make records in accordance with regulations while performing self-inspection.

4. In the normal processing process, it is found that there is an error in the size of the processed part, and we need to analyze it. If the tool is found to be good, we have to adjust the size according to the measurement result.


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